Comminutor



Dec. 23, 1941.

GOMMINUTOR Filed July 26, 1937 .A. c. DURDIN, 3D

Dec. 23, 1941. A. c. DURDIN, 3D 2,267,088

' l coMMINUToR Filed July 26, 1937 2 Sheets-sheet 2 Patented Dec. 23,1941 parra svi-MES. P

Augustus C. Dui-din, III, Chicago, Ill., assigner to Chicago PumpCompany, Chicago, Ill.,l a corporation of Illinois Application July 26,1937, Serial No. 155,710

(Cl. Zlib-152) 13 Claims.

' 'I'his invention relates to comminutors and particularly tocomminutors oi the rotary screen type, which are employed for commutingsolids vcarried by sewage. Certain disadvantages have heretofore beenexperienced with comminutors of this type. The rotating screen isprovided with 'teeth which carry solid materials against coniplementarycutting teeth on a stationary cutting bar, Most of the solid materialscarried by sewage tend to float on the surface of the liquid andexcessive wear is experienced by the teeth located in eccentric relationwithin the chamber I2, as shown in Fig. 2. The passage I3 bends andcutting bar adjacent the liquid level., A

further disadvantage which has been experienced in comminutors of thistype is the tendency for solid material, and particularly pieces of woodof substantial size, to become jammed between.

the screen and the basin in which it operates. A further disadvantage inprior comminutors is that in some cases elongated oating pieces ofdebris iioat through the slots without being engged by the teeth.

The principal object of the present invention is to provide an improvedcomminutor in which these disadvantages are eliminated.

Other objects, advantages and capabilities of the invention will appearfrom the following dey scription oi a preferred embodiment thereof,

takenin conjunction with the accompanying drawings, in which: g

Figure 1 is an elevational View, partly in section, of a comminutorembodying my invention,

and associated channels which supply sewage to the comminutor andreceive sewage therefrom after passing through the commi-nutor;

Fig. 2 is a plan view of the comminutor chamber, with the comminutorvremoved;

Fig. 3 is a sectional detail, taken onthe line 3-3 of Fig. 2;

' Fig. 4 is a sectional detail, taken on the line'vi 5 5 of Fig. 2;

Fig. 5 is a sectional detail, taken on the line with a downwardlydirected channel i3 which is cylindrical in plan and itsV bottom isprovidedv s upwardly again, as shown in `Fig. 1, and communicates with achannel I4 which conveys the screened sewage away.

At the upper edge of the passage I3, the .bottom of the chamber I2 isprovided-with an annular reinforcing member I5 .which is rigidly securedto the concrete from which the channel I0, chamber I2, passage I3 andchannel I4 may be made. The incoming channel I0 may be provided in itsbottom with a sump I6 in 'which is located a bucket Ilfor the receptionof heavy debris, such as stones, pieces of iron. and the like.

The comminutor or screen is mounted above 'the annular member I5. Thiscomminutor-may suitably comprise a cylindrical screen I8 whichterminates near the reinforcing member I5, vas bestJ shown-in Fig. '7.An annular member IS of angularcross-section is secured to thereinforcing member l5 so that itlies around the lower end of 'thecylindrical screen I8. The annular member I9 is provided with a flexiblemember, for example an annular strip of rubber 20, which bears againstthe outer wall of the cylinder at its lower end. The screen I8 may bemade integral.

and is provided with a plurality of vertical series ofY slots 2l throughwhich the liquid may pass inwardly sozas to escape down the conduit I3.

Between the adjacent series of slots 2 i, the screen I8 comprisescontinuous vertical strips 22 upon which may be mounted cutting teeth23. The screen I8 is adapted to be driven by a motor 24 and is suspendedfrom a rigid unit which may be carried by beams 25 which extend acrossthe chamber I2. The upper part of the vscreen 22 is enclosed within ahousing 2B which is rigidly secured to a column 21-which extendsdownwardly along one side of the screen at the position 23 in Fig. 2.Upon the column 21 are mounted cutter bars 2t which are adapted tocooperate with the teeth 23. It may here be noted that a plurality ofthe teeth 23 are mounted on each vertical strip 22 and that those onadjacent strips 22 are-staggered in vertical direction. Consequently,only a few teeth cut eachtime that one of the strips 23 passes thecutter bars 29, but each tooth of the cutter bars 29 cooperates with theteeth 23 to the same extent during the operation of the machine. vItwill be noted, with special reference to Fig. 2, that incoming sewage isdirected through the mouth I I' into a chamber which is hook shape inplan and which is reduced in Width'in the direction of the iiow. Iarrange the motor 24 to drive `the SQreen I8 in the opposite direction;that is,

in the direction opposite to the direction in which the width of theliquid passage decreases. It will readily be seen with reference to Fig.2 that if a piece of lumber oats down in the sewage and tends to moveinto the decreasing passage in the direction of the flow, then it willcome into contact with certain of the teeth 23,and will be movedoutwardly and drawn by these teeth into a position adjacent the cutterbars 29. Owing to the engagement between the teeth 23 and the teeth ofthe cutting bars 29, small pieces are cut out of the piece of lumber andthis procedure continues until the piece of lumber is disintegrated tothe extent that all the pieces may pass through the screen 22.

'I'he manner in which the passage around the comminutor decreases in thedirection of ilow has been previously described. This decreasecompensatesfor the water which flows through the screen and tends tomaintain the level of the liquid constant so that a greater capacity ofliquid ilow can be obtained. This action is also accentuated by aprogressive building up of the channel at the bottom. This is shown inFig. 3. The bottom of the chamber lz has a relatively low slope at theposition near the beginning of the reducing passage. As shown in Figs.4, 5 and 6, the slope at the bottom becomes steeper and steeper in thedirection of the flow until, as shown in Fig. 6, the slope at the bottombeyond the reinforcing member i5 is approaching the vertical. Owing tothe lling up of the decreasing passageway and the high level of liquidmaintained therein, the liquid flowing inwardly through the screen setsup a swirling or rotation of the liquid in the reducing passage. Thister bars 29. vThe cutting action of the comminutor is, .'therefore,distributed over the submerged portion of the screen I8 and the cutterbars 29 and is not located to an excessive degree adjacent the liquidlevel.

aac'aoss site to the direction of said ilow and toward the open end ofsaid path.

2. A comminutor comprising a chamber, a conduit for supplying liquidthereinto, a cylindrical screen rotatably mounted within and ineccentric relation to said chamber, an eduction outlet 4for liquidpassing inwardly through the screen, cutting means on said screen andstationary cutting means cooperating therewith, said chamber and screendefining between them a curved path into which incoming liquid isadapted to iiow, said path decreasing in width in the direction of now,and means for driving said screen in a direction opposite to thedirection of flow.

3. A comminutor comprising a chamber, a conduit for supplying liquidthereinto, a cylindrical screen rotatably mounted within and ineccentric duit for supplying liquid thereinto, a cylindrical.

screen rotatably mounted within and in eccentric relation to saidchamber, an eduction outlet from 'Ihis rotation or swirling produced inthe com- I minutor chamber also brings elongated solid material to thedrum at right angles to the slots, thereby reducing the tendency of suchmaterial to align itself'parallel to the slots and pass through theslots uncut.

Although the invention has been disclosed in connection with thespecific details of a preferred embodiment thereof, it must beunderstood that such details are not intendedto be limitative vof theinvention except in so far as set forth in the accompanying claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent ofthe United States is: v

1. A comminutor comprising a chamber, a conduit for supplying liquidthereinto, a cylindrical screenrotatably mounted within and in eccentricrelation to said chamber. an eduction outlet for liquidk passing throughthe screen, said chamber having a wall shaped to define between it andsaid screen a curved path open at one end and cooperating` therewithlocated near the open end of the said path, and means for driving saidscreen and its cutting means in a direction oppesaid chamber below saidscreen for the escape of liquid passing inwardly through the screen,cutting means on said screen, Astationary cutting means cooperatingtherewith, said chamber and screen defining between them 'a curved pathinto which incoming liquid is adapted toflow, the bottom of said chamberbeing sloped downwardly towards the screen and outlet. saidslope-becoming greater in the direction of iiow, and means for drivingsaid screen in a direction opposite duit for supplying liquid thereinto,a cylindrical screen rotatably mounted within and in eccentric relationto said chamber, an eduction outlet below said screen for -liquidpassing inwardly through the screen, cutting means on said screen andstationary cutting means cooperating therewith, said chamber and screendefining between them a curved path into which incoming liquid isadapted to flow, said path decreasing in width in the direction of ow,the bottom of said chamber sloping downwardly towards the screen andoutlet,4 the slope becoming greater as said path narrows in thedirection of flow, and means for driving said screen. Y

6. A comminutor comprising a chamber, a conduit for supplying liquidthereinto, a cylintirical screen rotatably mounted within andin'eccentrlc relation to said chamber. an eduction outletbelow saidscreen for liquid passing inwardly through the'screen, cutting means onsaid screen and stationary cutting'means cooperating therewith, vsaidchamber and screen defining between them a curved path into whichincoming liquid is adapted to now, said path decreasing in width in thedirection of flow, the bottom of said chamber sloping downwardly towardsthe screen and outlet,.the slope becoming greater assaid path narrows inthe direction ofow, and means for drivingsaid screen in a directionopposite to the direction of flow.

7. A comminutor comprising a substantially lround chamber, a conduit forsupplying liquid 2,sc7,oss

y thereinto, a cylindrical screen rotatably mounted chamber and screendening between them a curved path into'which the incoming liquid isadapted to ilow, said path decreasing in width-in A means adjacent saidstationary cutting means .preventing ow through that position, said thedirection of flow, the bottom of'said chamber `.sloping downwardlytowards thescreen and outlet, the slope becoming greater as the pathnarrows in the direction of now, and means for'drlving 'said screen.

8. A comminutor comprising a substantially round chamber, a conduit forsupplying liquid thereinto, a cylindrical screen rotatably mountedwithin and in eccentric relation to said' chamber,

screen drum, causing said liquid to swirl axially downwardly over saiddrum while a portion of the liquid passes into the drum, whereby thesolids are submerged by the swirling of the liquid in said path and areheld against the drum by the liquid flowing thereinto, rotating the drumin a direction opposite the direction of the ilow in said path, andcomminuting the submerged solids carried by the drum.

11. The method ofcomminuting solids carried by liquid which consists incausing said liquid and the solids carried thereby to flow intoand outof a circulating path, causing the detained portions of the liquid andsolids carried thereby to circulate upwardly and downwardly alongdifferent paths, temporarily stopping said solids at various depthsalong a submerged portion of said path, cutting from said solids smallportions thereof at successive stoppings of said solids until such slidaare completely comminuted, and removing the cut oif and comminuted partsof said an eduction outlet below saidscreen for liquid passing inwardlythrough the screen, cutting means on -said screen, stationary cuttingmeans cooperating therewith located adjacent said conduit and near theposition of greatest cross section between the screen and the chamberwall, means adjacent said stationary cutting means preventing iiowthrough that position, said cham-1 ber and screen deiining between thema curvedpath into which the incoming liquid is adapted to ilow, saidpath decreasing in width in the direction-oi' dow, the bottom of saidchamber 4sloping downwardly towardsl the screen and outlet, the slopebecoming greater as the path narrows in the direction o! flow, and meansfor driving said screen in a directionopposite to the direction of flow.

9. 'I'he method-of comminuting solids carried by liquids which consistsin causing said liquid to flow in a converging arcuate path around ascreen drum, causing said liquid to swirl upwardly at distances from thesurface of said drum and downwardly over the surface of said drum whilea portion of the liquid passes into the drum, whereby the normallyfloating solids are submerged and the normally sinking solids are movedto various heights in said path by the -swirlingiof the liquid in saidpath said solids are temporarily held against the drum atV variousheights by the liquid flowing thereinto, rotating the drum, andcomminuting the submerged solids carried by the drum at said heights.

10. The method oi comminuting solids carried by liquids which consistsin causing said liquid to iiow in a converging arcuate path around asolids with .the flow of liquid fromsaid up and down circulating path.

l2. The method of comminuting solids carried portions of said solids intheir;l downward flow and at various positions belowthe surface of theliquid and repeating suchc ting operation upon successive arrivals ofthe so ds at their downwardly flowing positions, until the solids havebeen reduced in size to substantially the size of v the portionstheretofore cutfrom the solids and removing the cut oif portions ofthesolids and finallyV the remainingpiecqs, of lthe solids from the up anddown circulating path.

13. The method of by a owing lii'illidV st which consists in causingnormally floating and normally sinking solids of said stream to becirculated upwardly and downwardly along diiferent paths andhorizontally in one direction along a curved path. temporarily stoppingsaid solids at various depths AUGUSTUS CDURDIN. m.

mminuting solids carried

